i did lol, or i reverse it again back then xd
I have not tried the game on windows 11 and likely never will, but unless the OS actually breaks the game, if you're using the actual english exe from either one of the later releases or the one posted here some time after game launch, and *not* the exe from the JP drm-free release, you should not *need* JP locale.
I've had no trouble running this game on windows 10, various linux versions and even winlator on a phone with and without JP locale. Complete save works in those places too, the problem lives elsewhere. You could try using the ResetConfig.exe in the game folder and see if that helps?